The U.N. High Commissioner for Refugees said Wednesday that violence and terrorism sent 14,000 Nigerians fleeing for their lives to neighboring Chad during January.

Islamic Boko Haram militants in northern Nigeria seized a military base and attacked the town of Baga along Lake Chad early this month. Some reports put the death toll in the thousands.

Many of the Nigerian refugees told U.N. officials terrifying tales of the Boko Haram attack, including accounts of militants shooting people who were trying to escape in boats. One man said he saw the bodies of women and children floating in the lake.

The U.N. recently built a refugee camp near Bagasola, Chad. Its refugee agency expects 30,000 Nigerians to arrive in Chad before the end of the year.

Boko Haram's terrorist campaign to set up an Islamic state in Nigeria has killed thousands since 2009.